Dietary caffeine consumption and withdrawal: Confounding variables in quantitative cerebral perfusion studies?
Dietary caffeine consumption and withdrawal: Confounding variables in quantitative cerebral perfusion studies?
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DOI：
10.1148/radiol.2271012173
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发表时间：
2003-04-01
期刊：
影响因子：
19.7
通讯作者：
Moody, DM
中科院分区：
文献类型：
--
作者：
Field, AS;Laurienti, PJ;Moody, DM
目得：通过一项随机、盲法、安慰剂对照研究，评估饮食中咖啡因摄入和戒断对脑血流量（CBF）的影响。（16名男子，4名妇女;年龄范围，24-64岁）归类为低（平均41 mg/d）或更高（平均648 mg/d）咖啡因使用者接受了两次定量流量敏感交替反转恢复灌注磁共振（MR）成像：一天服用咖啡因（250 mg）后90分钟，另一天服用安慰剂后90分钟（随机平衡设计）。在给药之前，先进行30小时的咖啡因戒断，以诱导高咖啡因使用者戒断。定量CBF图是分割的灰质（GM）-白色物质（WM），并进行感兴趣区域分析，以获得WM、前循环GM（AGM）和后循环GM（PGM）中的平均CBF。通过使用双向重复测量方差分析，区域CBF数据进行了测试，咖啡因和安慰剂之间的受试者内差异和饮食咖啡因习惯相关的受试者之间的差异。结果：在所有受试者中，咖啡因使CBF（P <0.05）降低23%（AGM，PGM）和18%（WM）。高咖啡因使用者的安慰剂（戒断）后CBF比低咖啡因使用者高31%（AGM）和32%（WM）（PGM，不显著）（P <0.05）。在AGM中，咖啡因摄入后平均CBF减少在高剂量使用者中为26%，而在低剂量使用者中为19%（P <0.05; PGM和WM，无显著性）。咖啡因摄入量的增加预示着所有地区CBF的增加（P <或等于0.05）：r = 0.79（AGM），0.57（PGM）和0.76（WM）。饮食中咖啡因的使用并不能预测CBF对咖啡因的反应。结论：饮食中咖啡因的消耗和戒断是脑灌注和功能性MR成像的潜在混杂变量。(C)RSNA，2003年。
PURPOSE: To evaluate the effects of dietary caffeine intake and withdrawal on cerebral blood flow (CBF), as determined from a randomized, blinded, placebo-controlled study.MATERIALS AND METHODS: Twenty adults (16 men, four women; age range, 24-64 years) categorized as low (mean, 41 mg/d) or high (mean, 648 mg/d) caffeine users underwent quantitative flow-sensitive alternating inversion-recovery perfusion magnetic resonance (MR) imaging twice: 90 minutes after a dose of caffeine (250 mg) on one day and after a dose of placebo on another day (randomized counterbalanced design). Doses were preceded by 30 hours of caffeine abstinence to induce withdrawal in high caffeine users. Quantitative CBF maps were gray matter (GM)-white matter (WM) segmented and subjected to region-of-interest analysis to obtain mean CBF in WM, anterior circulation GM (AGM), and posterior circulation GM (PGM). By using two-way repeated-measures analysis of variance, regional CBF data were tested for within-subject differences between caffeine and placebo and for between-subject differences related to dietary caffeine habits. Linear regression was used to determine whether dietary caffeine use predicts CBF or CBF response to caffeine.RESULTS: Caffeine reduced CBF (Pless than or equal to.05) by 23% (AGM, PGM) and 18% (WM) in all subjects. Postplacebo (withdrawal) CBF in high caffeine users exceeded that in low users (Pless than or equal to.05) by 31% (AGM) and 32% (WM) (PGM, not significant). Mean postcaffeine CBF reduction in AGM was 26% in high users versus 19% in low users (Pless than or equal to.05; PGM and WM, not significant). Increasing caffeine consumption predicted higher CBF (Pless than or equal to.05) in all regions: r = 0.79 (AGM), 0.57 (PGM), and 0.76 (WM). Dietary caffeine use did not predict CBF response to caffeine.CONCLUSION: Dietary caffeine consumption and withdrawal are potential confounding variables in cerebral perfusion and functional MR imaging. (C) RSNA, 2003.